Solar Battery Guides
Plain-English help with amp-hours, watt-hours, inverter current, LiFePO4 charging, cold protection, wiring, and bank sizing.
Frequently Asked Questions
What does amp-hour capacity mean?
Amp-hours describe charge, not energy by themselves. Multiply nominal voltage by amp-hours to estimate watt-hours: a 12.8V 100Ah LiFePO4 battery is about 1,280Wh before practical reserve and system losses.
How do I calculate battery runtime?
Divide usable battery watt-hours by the load's actual watts, then account for inverter and wiring losses. Runtime falls when loads cycle differently than expected, temperature reduces available energy, or the BMS reaches a current or voltage boundary.
How large should my battery cables and fuse be?
Size conductors for expected continuous current, allowed voltage drop, insulation temperature, installation method, and fault protection. The fuse protects the conductor and must interrupt the available fault current. Follow the battery, inverter, and applicable electrical requirements or use a qualified installer.
Can a solar charge controller charge LiFePO4?
Yes when it has a compatible lithium profile or correctly adjustable voltage settings. Disable lead-acid equalization, follow the battery maker's current and voltage limits, and ensure charging stops at unsafe low temperatures.
What is a battery BMS?
The battery-management system monitors cell voltage, current, and often temperature, then disconnects charge or discharge when a limit is reached. It is a last line of protection, not a substitute for correct charger settings, fuses, cables, or system design.
When should I use a battery-bank calculator?
Use it before selecting products to estimate energy capacity and current requirements. Treat the result as a starting point, then verify autonomy, peak loads, temperature, solar availability, charging time, reserve, exact-model BMS limits, and future expansion.